Forest Resource Measurement and Inventory Flashcards

The Doyle log rule consistently underestimates actual lumber yield compared to the Scribner and International rules because:

Answer: Its formula overpenalizes small-diameter logs and underestimates large-diameter logs relative to actual yield

Doyle's algebraic formula (D-4)²×L/16 dramatically underestimates yield for small logs and slightly overestimates very large logs due to the constant subtraction of 4 inches.

In remote sensing-assisted inventory, 'imputation' techniques such as k-NN (k-nearest neighbor) are used to:

Answer: Transfer field-measured attributes to unsampled pixels based on spectral similarity

k-NN imputation assigns field plot attributes to all mapped pixels by finding spectral or structural nearest neighbors among measured plots.

Which of the following describes the primary use of a 'growth and yield model' in forest resource management?

Answer: Projecting future stand conditions under different management scenarios

Growth and yield models project how stand attributes (volume, BA, density) will change over time under specified treatments, supporting long-term planning.

The 'quadratic mean diameter' (QMD) of a stand is calculated as:

Answer: DBH of the tree with basal area equal to mean stand BA

QMD is the diameter of the tree whose basal area equals the average basal area per tree, mathematically equivalent to the square root of mean squared diameters.

In a two-phase (double) sampling design for forest inventory, the large first-phase sample is typically used to:

Answer: Collect auxiliary information cheaply to stratify or calibrate the smaller, expensive second phase

Double sampling uses a large, inexpensive first phase (e.g., aerial photo interpretation or LiDAR metrics) to gather auxiliary data that improves efficiency of the costly second-phase field measurements.

A forester measures a tree's total height as 85 feet and finds the height to a 6-inch top diameter at 62 feet. What is the merchantable height?

Answer: 62 feet

Merchantable height is the height to the minimum usable top diameter, which in this case is 62 feet — not the total height of 85 feet.

The 'stocking guide' for a managed forest stand is best described as a diagram showing:

Answer: The relationship between stand density (TPA or BA) and QMD defining zones of overstocking, full stocking, and understocking

A stocking guide (or density management diagram) plots TPA against QMD with curves showing maximum, optimal, and minimum stocking zones to guide thinning decisions.